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Related papers: $\textit{A priori}$ and $\textit{a posteriori}$ er…

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In this paper, on the basis of a (Fenchel) duality theory on the continuous level, we derive an $\textit{a posteriori}$ error identity for arbitrary conforming approximations of a primal formulation and a dual formulation of variational…

Numerical Analysis · Mathematics 2024-10-25 Harbir Antil , Sören Bartels , Alex Kaltenbach , Rohit Khandelwal

Convex duality has been leveraged in recent years to derive a posteriori error estimates and identities for a wide range of non-linear and non-smooth scalar problems. By employing remarkable compatibility properties of the Crouzeix-Raviart…

Numerical Analysis · Mathematics 2026-02-05 P. A. Gazca-Orozco , A. Kaltenbach

In this paper, we propose a general approach for explicit a posteriori error representation for convex minimization problems using basic convex duality relations. Exploiting discrete orthogonality relations in the space of element-wise…

Numerical Analysis · Mathematics 2023-07-11 Sören Bartels , Alex Kaltenbach

In this paper we study the a posteriori bounds for a conforming piecewise linear finite element approximation of the Signorini problem. We prove new rigorous a posteriori estimates of residual type in $L^{p}$, for $p \in (4,\infty)$ in two…

Numerical Analysis · Mathematics 2024-04-02 Ben S. Ashby , Tristan Pryer

A posteriori error estimates are an important tool to bound discretization errors in terms of computable quantities avoiding regularity conditions that are often difficult to establish. For non-linear and non-differentiable problems,…

Numerical Analysis · Mathematics 2024-06-12 Sören Bartels , Alex Kaltenbach

In convex optimization, duality theory can sometimes lead to simpler solution methods than those resulting from direct primal analysis. In this paper, this principle is applied to a class of composite variational problems arising in…

Optimization and Control · Mathematics 2010-06-22 Patrick L. Combettes , Dinh Dung , Bang Cong Vu

This article develops a numerical approximation of a convex non-local and non-smooth minimization problem. The physical problem involves determining the optimal distribution, given by $h\colon \Gamma_I\to [0,+\infty)$, of a given amount…

Numerical Analysis · Mathematics 2025-05-08 Harbir Antil , Alex Kaltenbach , Keegan L. A. Kirk

The primal-dual gap is a natural upper bound for the energy error and, for uniformly convex minimization problems, also for the error in the energy norm. This feature can be used to construct reliable primal-dual gap error estimators for…

Numerical Analysis · Mathematics 2019-02-12 Sören Bartels , Marijo Milicevic

In this paper, we develop a new residual-based pointwise a posteriori error estimator of the quadratic finite element method for the Signorini problem. The supremum norm a posteriori error estimates enable us to locate the singularities…

Numerical Analysis · Mathematics 2024-01-05 Rohit Khandelwal , Kamana Porwal , Tanvi Wadhawan

Motivated by problems in contact mechanics, we propose a duality approach for computing approximations and associated a posteriori error bounds to solutions of variational inequalities of the first kind. The proposed approach improves upon…

Numerical Analysis · Mathematics 2014-10-09 Zhenying Zhang , Eduard Bader , Karen Veroy

A new technique of residual-type a posteriori error analysis is developed for the lowest-order Raviart-Thomas mixed finite element discretizations of convection-diffusion-reaction equations in two- or three-dimension. Both centered mixed…

Numerical Analysis · Mathematics 2015-03-26 Shaohong Du , Xiaoping Xie

We combine a systematic approach for deriving general a posteriori error estimates for convex minimization problems based on convex duality relations with a recently derived generalized Marini formula. The a posteriori error estimates are…

Numerical Analysis · Mathematics 2022-04-25 Sören Bartels , Alex Kaltenbach

In a previous work, we introduced a discretization scheme for a constrained optimal control problem involving the fractional Laplacian. For such a control problem, we derived optimal a priori error estimates that demand the convexity of the…

Optimization and Control · Mathematics 2016-03-31 Harbir Antil , Enrique Otarola

We consider a Markov chain approximation scheme for utility maximization problems in continuous time, which uses, in turn, a piecewise constant policy approximation, Euler-Maruyama time stepping, and a Gauss-Hermite approximation of the…

Optimization and Control · Mathematics 2020-01-07 Athena Picarelli , Christoph Reisinger

Variational inequalities play in many applications an important role and are an active research area. Optimal a priori error estimates in the natural energy norm do exist but only very few results in other norms exist. Here we consider as…

Numerical Analysis · Mathematics 2015-07-28 Olaf Steinbach , Barbara Wohlmuth , Linus Wunderlich

We present an a posteriori estimator of the error in the L^2-norm for the numerical approximation of the Maxwell's eigenvalue problem by means of N\'ed\'elec finite elements. Our analysis is based on a Helmholtz decomposition of the error…

Numerical Analysis · Mathematics 2016-02-02 Daniele Boffi , Lucia Gastaldi , Rodolfo Rodríguez , Ivana Šebestová

In this paper we study an a posteriori error indicator introduced in E. Dari, R.G. Duran, C. Padra, Appl. Numer. Math., 2012, for the approximation of the Laplace eigenvalue problem with Crouzeix-Raviart non-conforming finite elements. In…

Numerical Analysis · Mathematics 2014-11-11 Daniele Boffi , Ricardo G. Durán , Francesca Gardini , Lucia Gastaldi

The heart of the a priori and a posteriori error control in convex minimization problems is the sharp control of the differences of discrete and exact minimal energy. Conforming finite element discretizations for p-Laplace type minimization…

Numerical Analysis · Mathematics 2026-04-23 Carsten Carstensen , Ngoc Tien Tran

This paper is concerned with the two--phase obstacle problem, a type of a variational free boundary problem. We recall the basic estimates of Repin and Valdman (2015) and verify them numerically on two examples in two space dimensions. A…

Numerical Analysis · Mathematics 2016-06-06 Farid Bozorgnia , Jan Valdman

This work deals with the a posteriori error estimates for the Darcy-Forchheimer problem. We introduce the corresponding variational formulation and discretize it by using the finite-element method. A posteriori error estimate with two types…

Numerical Analysis · Mathematics 2022-02-24 Georges Semaan , Toni Sayah , Faouzi Triki
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